We plan to collect 900 volunteer post infarction patients, most of whom we believe from our most recent studies will exhibit Type A behavior pattern. These patients will be randomly divided into a control group of 300 patients who will be encouraged to take all generally accepted medical prophylactic measures to prevent a second serious cardiac epidsode during a five year period of study. The experimental group of 600 patients also will be encouraged to take the same medical prophylactic measures but in addition will receive special counseling designed to modify Type A behavior pattern when found to be present. The objectives of the study are to determine (1) what percentage of Type A post infarction patients can be counseled to modify significantly their behavior pattern, (2) the identifying profile of these patients and conversely that of those patients who did not or could not modify their behavior pattern and (3) whether the incidence of recurrent infarction or cardiac death will be significantly less in patients whose Type A behavior pattern has been modified than in patients whose Type A could not be modified.